Theorem impbir | index | src |

theorem impbir (a b c: wff): $ a -> (c <-> b) $ > $ a /\ b -> c $;
StepHypRefExpression
1 hyp h
a -> (c <-> b)
2 1 bi2d
a -> b -> c
3 2 imp
a /\ b -> c

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)